Gear-cutting machine



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UNITED sTA TESU PATENT OFFICE.

nowlinnn. COLMA-N, OFnOOI'IFOItn, ILLINOIS, AssIenoa TO' nAnnER-ooLiuAn COM- PANY, or ROCKFORD, ILLINOIS, A CORPORATION OF ILLINOIS.

GEAR-CUTTING MAGHINE.

Application filed August 8 1924. SerialNo. 730,839. Renewed Decemben 3, 1928 toothed bodies of revolution, by providing a machine capable of generating the teeth of such gears with relatively great rapidity and a high degree of accuracy.

A. particular object of the invention is to provide a machine wherein the gears may be both roughed out and finished with one setting of the blanks upon their supports, thus obviating the inaccuracies which. are practically inevitable when a blank is trans- :lf'erred fromv the arbor on which it is supported during the roughing operation to another arbor for the finishing operation.

Another object is to prevent the introduction of inaccuracies in the work due to expansion caused by the heat generated in the cutting operation.

.A further Object is to provide a circulatory series of? blank supports arranged to travel. from a loading and unloading station to and past the cutting means and thence back to the loading and unloadinq station.

In the machine herein shown the Work supports travel. at a higher rate of speed. while moving to and away from the cutters than while traveling past the cutters. It is an object of this invention to provide means whereby a work support, when moving to the cutters, shall be prevented from strikinn; the work supports passing the cutters, thereby preventing vibration which .Would cause marks to .be left on the Work by the finishing cutter. I

Various other objects and advantages of thisinvention will. become apparent as the description proceeds.

In the accompanying drawings, Figure 1 is a plan view of a machine embodying the Features of this invention.

F ig'. 2 is an elevation of the loading side of the machine.

Fig.1. 3 is an: elevation of the opposite side of the machine.

Fig. a is a view 01' the roughing end of the machine.

Fin. 5 illustrates the finishing end of the machine. I

Fig. 6 is a fragmental plan view 01? the greard'oughing jinechanism, the chip guards J and 141 being omitted.

7 is a horizontal sectional view showlng more particularly the means for spacing the cars or work supports to prevent the transmission of shocks tothe work in process ofbeing finished. In Fig. 7, the righthand car is represented as having been a'rrested.

Fig. 8 is a View similar to that of Fig. 7 but showing the last-mentioned car as havmg been released.

Fig. 9 is a fragmental elevation, with the parts inthe position shown in Fig.

Figs; 10, 11 and 12 are, respectively, aside elevation, a plan View and an en'd VlQW of the linishingmechanism.

Fig. 13 is a horizontal plan section taken in the planes indicated the dotted line 13 13 of Fig. 5. i

Figs. 14, 15 and 16 illustrate the backlash pr'eventi'lig means, Figs. 1-1 and 15 beng); sectional views taken in the planes of lines 14t14: and 15-4 5, respectively, of Fig.

Fig. 17 is a horizontal View taken in the plane of line 17 l7 of Fig. 5. The chip guards 1 10 and 14.1 are Omitted in this view.

Fig. 18 is an underside View of the tinishing mechanism. i

Fig. 19 is a detail view of the planing cutter and its support. 1

F lg. 20 is a vertical sectional View of the finishing mechanism taken in the plane of line 20.-20 of Fig. 10. i

Fig. 21 is a fi'aginental view showing the parts. in the position occupied in Firi'. 20.

22 is a detail view of the finishing cutter and its support. i

Fig. 28 is a view similar to that of Fig. 20 but showing the parts in a different positron. p j i Fig. 241- shows the mechanism for withch'a'wing the finishing cutter out of contact with the work dfuringf its return stroke.

Fig. 25 is a vertical, sectional view showing both the roughing cutter and the .[inishing cutter, and illustrating also the master gearing.

Fig. 26 is a tran'mental vertical view of the finishing mechanism.

Fig. 27 is a i'ragmental transverse vertical sectional view through the machine,

showing the means for driving; the roughing enter and the screw by means at which the work-supporting cars are caused to pass the cutter.

Fig. 28 is a fragmental vertical sectional View showing the means for adjusting the roughing cutter.

] Fig. 29 illustrates the means for adjusting the finishing cutter.

Fig. is a fragmental plan view showing the means for driving the screw which advances the cars past the cutters and the means for driving the chain which picks up the cars after they leave said screw and moves them to the loading and unloading station, and thence back to the'head end of the screw. 1 V

Fig. 31 is an end elevation taken in the plane of line 31-31 of Fig. 30. i

Fig. 32 is a fragmental plan View showing the means for driving the before-mentioned chain. s

Fig. 33 illustrates one of the casters with which each car isprovided.

. "Fig. 34 is a sectional View in the plane a of line 3434t of Fig. 33, showing the roller bearing for said caster. I

The embodiment which has been selected to illustrate the invention comprises a milling cutter 1 having upon its periphery a plurality'of equ'i-distant annular series of cutter teeth 2 of rack tooth form, the length of the cutter being. at least equal to the circumference of the pitch circle of the gears to be formed; a planing cutter v3 of racktooth form for finishing the gear teeth roughed out by the cutter 1; a series of slides or cars 4 to support the gear blanks; means to move the cars in an endless circuit to transport the blanks from a loading and unloading station, past the roughing cutter 1 and thefinishing cutter 3, back to the loadingand unloading station; and means to cause the blanks to revolve as they pass the .milling cutter and the planing cutter. I also contemplate placing between the roughing cutter 1 and the finishing cutter 3 a mechanism for rounding the corners of the teeth of the gears, in. which event the roughing and finishing cutters would, of course,

be spaced farther apart than as herein shown. 1

The diameter of the cutter 1 is made so great in comparison with the thickness 01" the blankto be roughed out that the concaving of thebottom of the tooth spaces and the sides of the teeth shall be very slight. In the disclosed embodiment of the invention, the ratio of the thickness of the blank to the radius of the cutteris 1 to 16.

While the cutter 1 may be constructed in various ways, I have herein shown the body of the cutter as formed of three transverse together. The periphery of each section '5 is provided with slots 6 (Fig. 25) to receive blades 7, each of which blades carries a plurality of cutter teeth 2. The blades 7 may be secured in the slots (3 in any preferred manner. In order to make the strains due to the cutting action more nearly uniform the blades 7 upon one section may be arranged in different angular relation from those on adjacent sections, as shown in Fig. (i. Rigidly secured to the cutter l is a worm wheel 8 (Fig. 27). The cutter and the worm wheel are mounted upon a shaft '9 which is carried in brackets 10 (Figs. 1

and 4-). The worm wheel 8 meshes with a worm 11 (Fig. 27) lixed upon a shaft 12, which shaft may be driven in any suitable way, as, for example, by means of a belt 13 (Fig. 2) running over a pulley 1.4; fixed on said shaft.

The blanks are. indicated at 7/ (Fig. 1). Each blank is rigidly secured to an arbor c (Fig. 25) by means of which the blank is supported during the roughing and finishing operations and during its travel in the. machine, and through which rolling movement is imparted to the blank while it is passing the cutters. Inasmuch as the length of the cutter 1 is at least equal to the circumference of the pitch circle of the gear to be cut, it is possible for the cutter to operate upon at least three blanks at the same time.

The blanks may be caused to travel past the cutters by anysuitable means, the preferred means including a plurality of cars 4 (Fig. Herein each car is shown as carrying five arbors 0. Each arbor is rotatably mounted in a bearing 15 in the car, the lower end of the arbor being supported on a thrust bearing 16. The upper end of the arbor is reduced in diameter to receive the blank I), the latter being clamped against a shoulder or flange 17 on the arbor by means of a nut 18 and a washer 15).

There may be any suitable provision for conveniently and rapidly removing the blank from the arbor. Herein is shown an ejector plunger 20 (Fig. 25) extending axially of the arbor, the lower end of the plunger being accessible to an automatic mechanism (not shown) or to a tool. in the hands of a workman t or driving the plunger upwardly; Downward movement of the plunger is limited by engagement of an annular shoulder 21 on the plunger with the screw-plug 22 that carries the thrust bearing 16. Pressure is transmitted from the plunger 20- to the blank by means of a plurality of rods 23, a washer 21 being interposed betwecn said rods and the hub of the blank.

The means for supporting and guiding the ears 4 while passing the roughing cutter and the finishing cutter comprises a massive casting 25, (Figs. 1, 2 and 27) extending parallel with the axis of the cutter 1 and providing upon the side which is adjacent to the cutters two vertical parallel guiding lltl 

